The present invention relates to the use of preparations for example rubber latex for the sealing of tires with punctures, and also to an apparatus for the introduction of a sealing preparation into the tires wherein the tire is pumped up to a pressure at which it can be driven, as well as tires with an integrated sealing preparation.
Various sealing preparations for tire punctures are available on the market. They mainly contain colloidal dispersions of polymers in an aqueous medium, known as latexes. Thus, by way of example, polystyrene-butadiene latexes, polyvinylacetate latexes, acrylic copolymer latexes, nitrile latexes and polychloroprene latexes, are used. Sealing preparations are also known which contain not water but rather tetrachloroethylene as the carrier medium.
For the introduction of the sealing preparation into the tire and for the pumping up of the tire to a pressure at which the tire can be driven, use is made of e.g., a spray can, an apparatus comprising a pressure tight container for the sealing preparation which contains a liquefied gas as the pressure source. Generally, a propane/butane mixture and is used as the liquefied gas, in rarer cases hydrochlorofluorocarbons also are used. Contains such as spray cans have at their outlet valve a hose, in which the other end thereof is provided with a screw adapter for the tire valve.
When a tire puncture arises, the sealing preparation is sprayed from the spray can via the tire valve into the interior of the tire and the tire is pumped up by means of a propellant gas to a specific pressure, which is at different levels, depending upon the leak. The tire is then driven for a few kilometers, depending on the nature of the defect, to distribute the sealing preparation in the interior of the tire and to seal off the defect.
In another apparatus the sealing preparation is located in a compressible flask, which is connected via an adapter to the tire valve from which the valve insert was previously removed. The sealing preparation is then injected into the tire by pressing the flask or bottle. After putting the valve insert in place, the tire is inflated again to a specific pressure with the aid of carbon dioxide cartridges.
The above described sealing preparations are not completely satisfactory. They can be relatively easily removed mechanically and are, in part, not adequately water resistant and do not result in a seal when the tire defect lies in the run out of the under-tread rubber, i.e. in the region between the tread and the side surface of the tire.
Difficulties arise with the apparatus for introducing the sealing preparation into the interior of the tire and for the pumping up of the tire. Thus, spray cans which contain propane/butane mixtures as the propellant gas only operate satisfactorily, depending on the mixing ratio, at temperatures down to about 0.degree. or somewhat below.
In the older German patent application 195 45 935.0, sealing preparations for tire punctures and apparatus for the application of the sealing preparation into the tire are described, which do not have the above named disadvantages. The sealing preparations comprise an agent which contains natural rubber latex, optionally together with additional rubber latexes or a rubber latex in combination with a compatible adhesive resin. Latexes of synthetic rubbers, such as stirene-butadiene rubber, acrylonitrile-butadiene rubber, ethylene vinylacetate rubber, chloroprene rubber, vinyl pyridine rubber, butyl rubber and also their mixtures, are named as rubber latexes which can be used together with natural rubber latex. The same synthetic rubber latexes and also natural rubber latex are quoted as rubber latexes which can be used in combination with an adhesive resin. Resins which have been added as a tackifier to elastomers, such as terpene phenolic resins, can be used as the adhesive resin.
The same patent application describes an apparatus for the sealing and pumping up of tires with punctures, in which a pressure-tight container is provided with an outlet valve for the sealing preparation and with a gas inlet. Furthermore, a pressure source is provided, so that gas under pressure can be introduced into the pressure-tight container via the gas inlet in order to introduce the sealing preparation into the interior of the tire and to pump up the tire.
Furthermore, a heat source for the heating up of the sealing preparation can be provided in the pressure-tight container and/or in the pressure source. Pressurised bottles with liquid or compressed gas and also air compressors are named as a pressure source.